1. Field of the Invention
The present invention relates to a working temperature control for an electric system such as computer system, and more particularly to a method for controlling a system to work at an appropriate temperature.
2. Description of Related Art
Please refer to FIG. 1. Because the functions of a central processing unit (CPU) 11 become stronger, the electricity consumption thereof also becomes higher; a cooling design is also more important to a notebook computer. The current design is to set a or several temperature values; it use thermal sensors 12 to detect the temperature of a system or a CPU 11, and then uses a controller 10 to execute several preset control modes when the temperature is higher than certain temperature values. The control mode comprises a cooling control such as the rotating speed control of a fan 13, a system consumption decreasing such as the efficiency lowering of the system or the CPU 11, and the power source shutting off such as the power source turning off of the system by controlling a power source circuit 14 when the temperature rises continuously to reach an extremely high temperature so as to attain to the protection function.
There are many patents concerning controlling a computer system to work at an appropriate temperature. For example, U.S. Pat. No. 6,965,175 discloses a dynamic temperature control method for a computer system; it utilizes a microcontroller to obtain the energy consumption value and the temperature of the computer system to control a fan module to rotate in a proper range. Taiwan Invention Patent No. I246,392 discloses a temperature measurement method and an apparatus thereof; it is used for measuring temperature inside a case of a personal computer and the surrounding thereof so as to decide the rotating speed of a fan to process cooling. Taiwan Patent Publication No. 572,257 discloses a notebook computer with temperature adjustment functions; it allows a system to emit a command to a output/input controller to lower automatically the out-of-band frequency and the working voltage of the microprocessor to force the consumed power of the microprocessor to be decreased to attain to the temperature lowering function when a temperature sensor detects that a temperature value reaches a temperature value preset by the microprocessor. Taiwan Patent application No. 502,148 discloses a system and method for immediately controlling temperature of a central processing unit of a notebook computer; it comprises executing a preset module and a warning temperature value is set through the preset module; executing a detection module, the temperature of the central processing unit at that time is immediately detected through the detection module to obtain a temperature value of the central processing unit at that time; and executing a temperature adjustment module, a judgment is processed through the temperature value at that time obtained in the detection module to dispatch a fan driving module to calculate a rotating speed that the fan should reach and then to start the fan.
Almost every controller in the current computer system cooling protection design decides a corresponding counterplot only depending on temperature detected through a temperature sensor. But, the influence of heat on the system is not merely a temperature value, heated time length is also an important factor. For example, the capacity and the life of a battery used in a notebook computer are decreased if it is used at a high temperature over a long period of time. Further, for example, although some plastic materials are not influenced at a high temperature in a short time, the characteristics thereof are also influenced if they ate at a high temperature over a long period of time.